Pedulla Esque Fretless Finish

I have a fretless jazz bass but the finish that is on the fingerboard right now doesnt give enought muuah. I was wondering how pedulla gets that glass like finish on the fingerboard. I have tried on a project bass just using polyurethane, but couldnt get that shiney finish and also couldnt make my bass get enough muaah. Any tips/tricks?